To provide added insights regarding age-related changes in CNS functioning, a variety of electrophysiological and behavioral measures have been obtained from 20 normal male adults in each of the following age ranges: 21-30, 41-50, 61-70, and 71-90 years. Subjects in the latter two groups were screened by a neurological examination. A battery of sensory-perceptual tests administered to each subject showed the following. No significant age effects were found for (1) Quick Test (a short IQ test), (2) spiral after-effect, (3) simple reaction time, and (4) speed of tapping although with the exception of (1) the trend was for poorer performance by older subjects. Significant decrements in the performance of older subjects was found for (1) complex reaction time, (2) accuracy of estimating the number of dots flashed on a screen, (3) critical flicker fusion, (4) stroup color test, and (5) Graham-Kendall Memory for Designs. With electrophysiological measures the following was observed. (1) The LPC or P300 wave in evoked potentials of older subjects was significantly delayed. (2) LPC amplitude did not change with age. (3) The EEG of the oldest subjects generated reliably less power than that of younger subjects. (4) EEG amplitude correlated 0.50 with visually evoked response amplitude.